SAN FRANCISCO--(BUSINESS WIRE)--ServiceSource® (Nasdaq: SREV), the global leader in recurring revenue management, today announced financial results for the second quarter ended June 30, 2015. “ServiceSource continued to execute in the second quarter and we exceeded expectations across all key financial metrics. Year over year our gross margin increased, operating expenses decreased and EBITDA improved dramatically. We drove operational efficiency, while increasing revenues on behalf of our clie